Portable furnace



March 22, 1932. J. A. MARTIN 1,850,466

' PORTABLE FURNACE Filed April 21, 1930 2 sheets-Sheet 2 INVENTOR.

fesse JWYf/z/'IZ BY n ATTORNEYS.

Patented Mai. 22, 1932 511A-TES JESSE A. MARTIN, OF lLGS ANGELES, (.'LALIEFORNIAI PORTABLE runNAcE Application led April 21,

This invention relates to gas furnaces for heating large spaces, such as halls, factories, warehouses, motion picture studios, out-ofdoors, and the like'.

The purpose of this invention is to provide a heating unit of large capacity which may be utilized for supplying heat to heat small portions of large space that would require an enormous amount of energy to heat the l0 entire space. In other words, this invention purports to provide a portable heating unit that may be moved about into different parts of a hall, factory, warehouse, motion picture studio or out-of-doors, to supply heat to cer- 5. tain portions of the space where it is most desired. This invention is particularly applicable and finds general usefulness in moving picture studios where greatfspace is required for erecting sets, and where a certain amount of heat is necessary for those participating ink the production of a picture.

In erecting sets for shooting scenes in the manufacture of motion pictures, it is at times necessary to use, temporarily, only a small part of a vast enclosure; for instance, a certain set maybe located in one corner of a studio building, while the set to be used subsequently is located in the opposite corner.

In order to maintain a propertemperature entire studio, but this becomes prohibitive in View of the cost. It is, therefore, an object of this invention to provide a portable heating unit of large capacity which may be moved about from spot to spot to temporarily supply heat in sufficient quantities to maintain a'proper temperature locally for those participating in the production of motion pictures. In addition to the above, there is a phenomenon peculiar to mot-ion picture photography that occurs when a scene is shot in cold atmosphere and the setting represents a warm interior, such as a warm ballroom full of people. It has been found in practice that if the airis to-o cold, the breath of th se participating in the scene, will conde se and photograph, thus producing the incongruous effect of frosty atmosphere in a Warm room. It, therefore, may become necessary to heat for comfort, it would be necessary to heat they 1930. Serial No. 445,871.

a certain part of a set before shooting the scene, in which event, the heat unit may be rolled into the spot to be later photographed, and then rolled out before-the picture is taken. It is, therefore, another object of this invention to provide a portable heating unit having iiexible gas and electrical connections which permit local movement of the unit to primarily heat a scene before the action of the picture takes place.

A noteworthy feature of this invention resides in the fact that the unit is so-constructed that the hot air is liberated at the base of the unit and, preferably, travels outwardly therefrom to rise by convection. The heat from the unit is, therefore, imparted to the lower layer of cold air along the iioor, and heats the lower Zone of cold air first, thus providing an efcient heating unit, in that the hot air is delivered directly at the feet of any persons that may be congregated about the unit.

Other objects and advantages will become apparent as the description proceeds in conjunction with the drawings in which- Fig. 1 is a perspective of the complete unit;- F Fig. 2 is a section taken on the line 2-2 of- Fig. 3 is a sectiontaken on the line 3-3 of Fig. 2; and 80 Fig. 4 is a diagram of the wiring system use f In its entirety, my device, as best illustrated in Fig. 1, comprises a casing, generally designated A, mounted upon casters shown at B. They casing A may be of any suitable configuration, but in this instance is shown as substantially square, and is provided on the upperend with a hood member designated C, which is shown as being substantially frustro-conical in shape. Mounted upon the hood member C is an air blowing arrangement D. The casing A is provided with handle members, suitably mounted thereon and peripherally spaced therefrom, for the double purpose of moving the unlt about, and also of preventing. persons. from leaning against the hot walls of the casing.

The lower part of the shell wall 1s left open, and is covered with a screening mem` ber E for the purpose of permitting air to flow downwardly and outwardly at this point. Heating means, generally designated F, is provided in the lower part of the casing A for su plying -heat to the apparatus.

More speci cally describing my apparatus, the foregoing generally designated parts will be taken up in the order set forth. The casmg or shell A, as before stated, may be of any suitable configuration, but is illustrated as being square, and is formed by building a frame of angle iron units, such asjshown at 12, and mounting within said frame a sheet metal lining 13. The lower part of the sheet lining 13 is stopped short of a base plate 14,

-as shown at 15, and the aforementioned screening member E is mounted to cover the space. Under certain conditions, the base plate 14 may be dispensed with and the hot air blown directly against the floor, but I have found it preferable to use a plate to prevent scorching of the floor or floor coverings. The top member C is likewise formed of sheet metal, and is suitably mounted upon the upper edge of the lining member 13. `As before stated, the shape of the member C is substantially frustro-conical, and has mounted upon the upper open end .thereof a screen cage 16 substantially circular in outline. Mounted within the screen cage 16 is the airblowing means D, which comprises a Amotor 17, suitably mountedin a spider arrangement 18 and carrying a direct connecting fan 19 I arranged to blow air substantially in the direction indicated by the arrows 20.

More specifically describing the burner means as apart of the heating means it is shown as comprising a iexible gas conduit 21 which conducts gas or other suitable fuel from a source of supply (not shown) to a valve shown at 22. The gas passes through the valve 22 and into mixing chambers 23 which lead to 'burners 23 in the interior of the'furnace. A stem 24 is provided on the valve 22, operable by the handle 25 of said valve, andoperates a conventional switch arrangement shown at 26. A ieXible conduit 27 houses-a pair of lead wires 28 and 29, which lead from a source of power not shown. The

electric circuit passes through the switch 26 and outward through the conduit 30 to aA thermostatically controlled switch 31. The lswitch' 31 is interposed directly in a stack 32 which conducts the combusted gases from the interior of a combustion chamber 36. As

shown, the thermostatically controlled switch 31'is`interposed in series in the circuit from the switch 26 to the mo'tor 17. vUnder this the structure described, with respect to the.

valve 22 andthe switch 26, itis apparent that the switch 26 closes the circuit to the motorv 17 only at the time that the valve 22 isopened,

It is also obvious that the motor 17 will not operate to blow air downwardly through the apparatus until the interior of the heating means F is brought to a proper temperature. Itis to be understood that although the thermostatic switch is placed in the stack 32, neyertheless, the temperature of the stack is proportional to the temperature of the heatingmeans F; and it requires only4 that the thermostatic element be adjusted to compensate for this difference. Therefore, the switch 31 is placed in the stack in order to make it more accessible. Such an arrangement will be appreciated as providing a`structure for the purpose described. y

Referring to the heating means F, located in the interior of the casing A, it is seen to comprise tubes 33 which extend through a ,v header arrangement 34, positioned in the upper part of the casing A. The tubes 33 are surrounded for a small part of their upper portion beneath the header 34 by concentrically arranged tubes 35 which conduct com busted gases from thecombustion chamber 36 into the header arrangement.

The header arrangement 34 leads into a .downcast portion 37 that terminates in a lateral extension 38 which passes outwardly through the lining 13 and enters the stack 32. The combusted gases produced in the chamber 36, from the burners 23', pass outwardly substantially in the direction of the dotted l through the screen E. This arrangement provides'a counter flow of drafts whereby a portion of the cold air is forced downwardly through the hot tubes 33 leadingV directly through the hot combusted gases, and a part is forced to flow over and around the exterior of the heating means. Such an arrangement ils will be readily recognized as providing a structure whereby the interchange of heat is most efficient andhot air is delivered at a point where it performs the most efficient service for the purpose of heating, as described in this invention.

Although I haveherein described 'aspecific embodiment of my invention, nevertheless I am aware'that certainmodifications and al-.

terations in the nature of refinements may be resorted to in the process of manufacture that would in no wise depart from the scope of thg specification or the purview of theappended claims. It is, therefore, my intention *45 ranged in said stack andadapted to control to' include all such modifications and alterations by this disclosure.

I claim as myV invention: Y

1'. A portable space heater comprising: a casing having a`peripheral opening about the lower portion thereof; 'a stack 'connected to said casing; casters mounted upon said casing; heating means in said casing; an electrically actuatedblower in the upper end of a gas burner and valved meansforcontrolling said burner; an electrically actuated blower in the upper end of said casing for blowing air downwardly through said heating means 5. A portableY space heater comprising: a casing mounted upon casters heating means in said casing; means for blowing cold air downwardly through said heating means and outwardly circuiu erentially of the base of said casing. A

In testimony whereof, I -have hereunto set my hand at Los Angeles, California, this 4th day of April, 1930. l

A.' MARA TIN. Y

and outwardly through said opening; a

thermostatically controlled switch arranged in said stack and adapted to control said blower in response to predetermined temperatures in said stack; and a second switch in series with said thermostatically controlled v switch arranged to be operated simultaneously with said valve.

l3. A space heater comprising: a casing having a peripheral opening about the lower portion thereof; a stack connected to said casing; casters on said casing; heating means in said casing, said heating means including Y a gas burner and valved means for controlling said burner; an electrically actuatedblower in the upper end of said casing for blowing air downwardly through said heating'means and outwardly through said opening; a thermostatically controlled switch arsaid blower in response to predetermined temperatures in said stack; a second switch in series with said thermostatically controlled switch arranged to be operated simultaneously with said valve; iexible conductors for connecting said second switchto a source of. electrical energy; and a flexible conduit Vfor connecting said valve to a source of gas.

4. Ina portable space heater having casters and heating means: an electrically actuated blower arranged to blow cold air downwardly through said heating means; a pair of switches arranged in seriesto control said blower, one of said switches being a thermostatically actuated switch arranged to -controlsaidblower in response to temperatures of said heat-ingymeans, the other of said switches being arranged to control said blower in accordance with the control of said heating means. 

